1. Field of the Invention
This invention relates to cleaning apparatus for removing residual developer and other particles from a developer-contact surface in an electrostatographic copier or printer. More particularly, this invention relates to such a cleaning apparatus that has a cleaning blade which uniformly conforms to the contour of the surface being cleaned.
2. Background Art
Electrostatographic process apparatus which, for example, produce or reproduce toned images on selected substrates by employing electrostatic charges and toner particles on an insulated reusable photoconductive surface, typically operate through a sequence of currently well known steps. These steps include (1) charging of the insulated photoconductive surface with electrostatic charges, (2) forming a latent image electrostatically on such surface by selectively discharging areas on such surface, (3) developing the electrostatic image so formed with developer particles including toner particles, (4) transferring the toned image to a suitable substrate for fusing thereon to form a permanent record, and (5) cleaning developer-contact surfaces in such an apparatus with a cleaning device that removes residual developer and other particles from such surfaces in preparation for similarly producing another image.
Such cleaning is necessary because during this process, several surfaces in addition to the photoconductive surface within the electrostatographic apparatus, come into contact with, and are contaminated by the image-forming developer particles, for example, toner particles. The quality of the images produced by such an electrostatographic apparatus therefore depends significantly on the effectiveness of the cleaning device in cleaning the photoconductive surface for example before it is reused.
Several types of cleaning devices, including brush-type and blade-type devices have therefore been developed. Such devices or apparatus are disclosed, for example, in U.S. Pat. No. 4,870,449 issued Sept. 26, 1989 to Brown; No. 4,827,311, issued May 2, 1989 to Bothner et al; and No. 4,501,620, issued Feb. 26, 1985 to Oda. Typically, the cleaning blade of a blade-type cleaning apparatus consists of a long, thin flexible strip of material such as steel having first and second long edges. The first long edge thereto, for example, is a cleaning edge for mounting in scraping engagement with the surface to be cleaned. The second long edge is a mounting edge for rigidly mounting such a blade to a support member. As mounted, it is desirable for the cleaning edge thereof to load uniformly against, as well as make uniform contact with, the surface to be cleaned. Typically, the surface being cleaned is moved past the cleaning edge of such a mounted blade.
Unfortunately, however, spatial misalignments are a common problem between the cleaning edge of such a mounted blade and the surface to be cleaned. Such misalignments can be due to unfavorable mounting tolerances and/or runouts of the surface to be cleaned. Further complicating this problem is the fact that a long thin blade which is conventionally mounted and loaded usually cannot readily flex simultaneously along its width as well as along its length dimensions. The net consequence of this fact is that the cleaning edge of the blade cannot uniformly contact or uniformly load against the surface to be cleaned. The end result of all of this is that there may be poor and ineffective cleaning of the surface to be cleaned, and images formed using the electrostatographic apparatus in which the particular cleaning apparatus is used may have artifacts or other defects.